Knowledge bases (KBs), such as Google Knowledge Graph, Wordnet , and Freebase  are important information resources, containing facts about the real world in the formof a large knowledge graph. Each fact in the knowledge base is represented as a resource description framework (RDF) triplet: (subject, predicate, object), where subject and object are considered entities represented as nodes in the graph, and predicate is considered as a relation between those entities represented as a directed edge between the nodes.
Knowledge graphs are used for a wide variety of natural language processing tasks, e.g. question answering, information retrieval, co-reference resolution, etc. However, the problem with such resources is that they are incomplete and lack reasoning capability, which inspired our work in this area.